I’ve copied and pasted this article because it shows just how rapidly changes are happening!  Classical and 2D computer animation are both options for hand held screens.
Written by Free Audio Books - Free audiobooks on November 19, 2009 – 9:14 pm -

The man behind SpongeBob SquarePants is testing out a new business model: launching an animated franchise on the iPhone -
instead of TV or film.

Hecht’s four-year-old independent studio, Worldwide Biggies, will debut Bigby, a new cartoon character that — rather than premiering as a half-hour weekly animated series on television — will make his first appearance as an iPhone game app.

Produced in partnership with online gaming giant Addicting Games, the Bigby game is based on an 8-year-old crime-fighting genius, who wears a bear suit, fights off pirates and dragons, and only eats chicken parmesan.